1. Field of the Invention
The present invention relates to an electronic parking brake device for vehicles and a control method therefor, and more particularly to an electronic parking brake device capable of receiving a sensing signal generated from a sensor on a road with a slope, thereby automatically achieving a parking-braking operation to provide safety and convenience to the driver, and a method for controlling the electronic parking brake device.
2. Description of the Prior Art
Referring to FIG. 1, a transmission gear shift lever of a manual parking brake device having a conventional construction is illustrated. Such a manual parking brake device is provided in a vehicle to prevent the wheels of the vehicle from rotating due to its thrust under a condition that there is no driver nor passenger in the vehicle in a parked or stopped state of the vehicle. As schematically shown in FIG. 1, the conventional parking brake device includes a manipulating lever coupled to a brake member via a wire. When the driver manually manipulates the manipulating lever, the wire is tensed to actuate the brake member. The brake member comes into frictional contact with the shaft of the wheels, thereby preventing the wheels from rotating. Thus, any thrust of the vehicle is avoided.
However, such a conventional parking brake device involves a problem in that the wire may be cut when the driver pulls the manipulating lever with an excessive force. The wire pulling force is proportional to the frictional contact force of the brake member against the wheel shaft. Although the vehicle is parked on a road with a slope, it may be thrusted where the slope of the road is very sharp unless the wire pulling force is high enough to obtain a very high frictional contact force of the brake member. In this case, there is a degradation in the safety of passengers in the vehicle and possible damage of the vehicle.